Large eddy simulations of a circular cylinder at Reynolds numbers surrounding the drag crisis
Large eddy simulations of a circular cylinder at Reynolds numbers surrounding the drag crisis
Large eddy simulations of the flow around a circular cylinder at high Reynolds numbers are reported. Five Reynolds numbers were chosen, such that the drag crisis was captured. A total of 18 cases were computed to investigate the effect of gridding strategy, domain width, turbulence modelling and numerical schemes on the results. It was found that unstructured grids provide better resolution of key flow features, when a ‘reasonable’ grid size is to be maintained.
When using coarse grids for large eddy simuation, the effect of the turbulence models and numerical schemes becomes more pronounced. The dynamic mixed Smagorinsky model was found to be superior to the Smagorinsky model, since the model coefficient is allowed to dynamically adjust based on the local flow and grid size. A blended upwind-central convection scheme was also found to provide the best accuracy, since a fully central scheme exhibits artificial wiggles which pollute the entire solution.
Mean drag, fluctuating lift and Strouhal number are compared to experiments and empirical estimates for Reynolds numbers ranging from 6.31 × 104 ? 5.06 × 105. In terms of the drag coefficient, the drag crisis is well captured by the present simulations, although the other integral quantities (rms lift and Strouhal number) less so. For the lowest Reynolds number, the drag is seen to be most sensitive to the domain width, while at the higher Reynolds numbers the grid resolution plays a more important role.
circular cylinder, drag crisis, high reynolds number, large eddy simulation
676-686
Lloyd, Thomas P.
4558987d-ec37-42e6-b043-7f9da7439e67
James, M.C.
aaf059b7-05ec-4560-be35-7fc1bfe46f07
Lloyd, Thomas P.
4558987d-ec37-42e6-b043-7f9da7439e67
James, M.C.
aaf059b7-05ec-4560-be35-7fc1bfe46f07
Lloyd, Thomas P. and James, M.C.
(2015)
Large eddy simulations of a circular cylinder at Reynolds numbers surrounding the drag crisis.
Applied Ocean Research, 59, .
(doi:10.1016/j.apor.2015.11.009).
Abstract
Large eddy simulations of the flow around a circular cylinder at high Reynolds numbers are reported. Five Reynolds numbers were chosen, such that the drag crisis was captured. A total of 18 cases were computed to investigate the effect of gridding strategy, domain width, turbulence modelling and numerical schemes on the results. It was found that unstructured grids provide better resolution of key flow features, when a ‘reasonable’ grid size is to be maintained.
When using coarse grids for large eddy simuation, the effect of the turbulence models and numerical schemes becomes more pronounced. The dynamic mixed Smagorinsky model was found to be superior to the Smagorinsky model, since the model coefficient is allowed to dynamically adjust based on the local flow and grid size. A blended upwind-central convection scheme was also found to provide the best accuracy, since a fully central scheme exhibits artificial wiggles which pollute the entire solution.
Mean drag, fluctuating lift and Strouhal number are compared to experiments and empirical estimates for Reynolds numbers ranging from 6.31 × 104 ? 5.06 × 105. In terms of the drag coefficient, the drag crisis is well captured by the present simulations, although the other integral quantities (rms lift and Strouhal number) less so. For the lowest Reynolds number, the drag is seen to be most sensitive to the domain width, while at the higher Reynolds numbers the grid resolution plays a more important role.
Text
2014_ITTC_cylinder.pdf
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Submitted date: 2014
Accepted/In Press date: 16 November 2015
e-pub ahead of print date: 24 December 2015
Keywords:
circular cylinder, drag crisis, high reynolds number, large eddy simulation
Organisations:
Fluid Structure Interactions Group
Identifiers
Local EPrints ID: 371932
URI: http://eprints.soton.ac.uk/id/eprint/371932
ISSN: 0141-1187
PURE UUID: 576c343f-a86c-48e3-bf6d-f45834b9ca8a
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Date deposited: 24 Nov 2014 13:52
Last modified: 14 Mar 2024 18:28
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Author:
Thomas P. Lloyd
Author:
M.C. James
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